Canine aggression to family members and familiar dogs

A recent study by researchers at Nationwide Children’s Hospital showed that there are about 12 genes associated with canine aggression toward an owner or a familiar dog. They concluded that these genetic traits are distinct from the genetic predisposition toward aggression to unfamiliar people and dogs.

It has been found that the genetics involved are common to all breeds of dogs making it easier to study.


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Carlos Alvarez, PhD, who is the main researcher at the Center for Molecular and Human Genetics in The Research Institute at Nationwide Children’s Hospital, feels that the genes are consistent with the neural pathway known as the amygdala to the hypothalamic-pituitary-adrenal axis.

Researchers feel that this genetic element is related to anxiety disorders in humans and hope that further research will show what kinds of medications will help both dogs and people.

This is an on-going research project. The fact that this type of aggression is genetically based is a good reason for people who plan to purchase a dog to investigate thoroughly the ethics of the breeder and the lines of the dog. If a person adopts a dog who shows this type of behavior they should immediately consult with a certified canine behavior consultant. You can find one at If my readers would like my brochure about how to find a good breeder and a quality dog, please emails me at There is no charge for the brochure.


Dog aggression may be related to hormone levels

According to research conducted by Evan MacLean at the University of Arizona and published in the journal Frontiers in Psychology they found that the hormones oxytocin and vasopressin may be linked to aggression in dogs. Both hormones are also found in humans.

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Dogs that tested to be more aggressive had higher levels of vasopressin. What is interesting is that further research of dogs bred to be assistance dogs who are bred specifically to be non-aggressive, had higher levels of oxytocin and higher oxytocin-to-vasopressin ratios. What this means is that oxytocin may help inhibit aggression.

Researchers also found that experience can influence the level of vasopressin in a dog. Often aggression results from a traumatic experience which alters the hormone levels resulting in a form of PTSD. On the flip side, positive experiences such as socialization with people and other animals in a non-threatening manner can raise the oxytocin levels.

The good news is that in humans, they are already using hormone therapies to help people with autism, schizophrenia and other problems such as PTSD. Perhaps this will lead to therapies for dogs that are extremely aggressive.